Surfactant Composition for Agricultural Chemicals

ABSTRACT

A surfactant composition for agricultural chemicals, containing fatty acid polyoxyalkylene alkyl ether expressed by the following general formula (I), 
       R 1 CO(EO) m (PO) n OR 2   (I)
 
     wherein the fatty acid polyoxyalkylene alkyl ether has a narrow ratio of 55% by mass or more, where the narrow ratio is expressed by the following formula (A): 
     
       
         
           
             
               
                 
                   
                     Narrow 
                      
                     
                         
                     
                      
                     ratio 
                   
                   = 
                   
                     
                       ∑ 
                       
                         i 
                         = 
                         
                           n 
                           
                             MAX 
                             - 
                             2 
                           
                         
                       
                       
                         i 
                         = 
                         
                           n 
                           
                             MAX 
                             + 
                             2 
                           
                         
                       
                     
                      
                     
                       Y 
                       i 
                     
                   
                 
               
               
                 
                   ( 
                   A 
                   )

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of PCT/JP2009/059459, filed on May22, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a surfactant composition foragricultural chemicals, which is suitably used as an emulsifier,dispersing agent, spreading agent, functional spreading agent(adjuvant), and water dispersible agent for agricultural chemicals.

2. Description of the Related Art

In order to allow agricultural chemicals to sufficiently exhibit theireffects, formulations of agricultural chemicals, such as bactericides,insecticides, acaricides, weed-killers, and plant growth regulators, aresuitably selected considering efficiency for spraying an agriculturalchemical for use, safety thereof, or the like. Among such formulations,an emulsified dispersion liquid of an agricultural chemical is expectedto be entirely and uniformly deposit on the target for spraying, and hasbeen used in the art. In order to disperse an agricultural chemical,which is generally an oily substance, in water, various surfactants havebeen used in the emulsified dispersion liquid of the agriculturalchemical.

Surfaces of leaves or stems of plants and surfaces of insects have asubstance or structure which repels of liquids, or prevents from beingwet by liquids. For example, on surfaces of plants, wax-lipoids aresecreted, or feathery fibers are closely grown. In another case, fineirregularities are present on surfaces of plants. Moreover, a layersimilar to a keratin is present on surfaces of pest insects. All ofthese materials have such qualities as to repel an aqueous dispersionliquid of agricultural chemicals. Due to this, there are cases where thesprayed agricultural chemical may not provide a sufficient effectthereof. Therefore, spreading agents and functional spreading agents(adjuvants) are used in agricultural chemicals for providingagricultural chemicals with enhanced qualities such as wetting ability,permeability, spreading, and fixing, to thereby increase chemicaleffects of the agricultural chemicals.

Conventionally, as these surfactants for agricultural chemicals,nonionic surfactants of various alkyl oxide adducts have been known. Forexample, a spreading agent for agricultural chemicals, which contains anonionic ester surfactant formed of specific fatty acid polyoxyalkylenealkyl ether, is disclosed in Japanese Patent Application Laid-Open(JP-A) No. 06-329503. An agrochemical spreader composition, which is asurfactant composition excellent in low-temperature stability isdisclosed in JP-A No. 2001-288006.

A surfactant for agricultural chemicals formed of a nonionic surfactantis generally used for formulating a fluid agricultural chemical, or iscommonly added to a fluid preparation of an agricultural chemical as afluid spreading agent for an agricultural chemical. Therefore, in actualpractices, such surfactant is required to have basic performances suchas solubility for dissolving an oil-soluble agricultural chemicalcomponent; low foamability and defoamability for improving handling atthe time of preformulation in a tank and at the time of spraying, andpreventing foaming (polluting) in rivers or the like; and permeabilityto surfaces of plants and the like, as well as stability which preventsprecipitation or separation of substances at the time of use, duringstorage at low temperature, or when the temperature is changed from lowtemperature to normal temperature.

BRIEF SUMMARY OF THE INVENTION

The present invention aims at solving various problems in the art, andachieving the following object. Specifically, the object of the presentinvention is to provide a surfactant composition for agriculturalchemicals, which has excellent surface activity (e.g. solubilizationability, dispersibility, permeability, low foamability, and defoamingability), excellent stability at low temperature, desirablebiodegradability, and excellent safety in the environment (e.g. nophytotoxicity and fish toxicity).

Means for solving the aforementioned problems are as follows:

<1> A surfactant composition for agricultural chemicals, containing:

fatty acid polyoxyalkylene alkyl ether expressed by the followinggeneral formula (I),

wherein the fatty acid polyoxyalkylene alkyl ether has a narrow ratio of55% by mass or more, where the narrow ratio is expressed by thefollowing formula (A).

R¹CO(EO)_(m)(PO)_(n)OR²  (I)

In the general formula (I), R¹CO is a C14-22 saturated or unsaturatedfatty acid residue; R² is a C1-3 alkyl group; m and n each express anaverage number of moles added, where m is an integer of 2 to 10, and nis an integer of 1 to 4; and EO expresses a structural unit of ethyleneoxide, and PO expresses a structural unit of propylene oxide, where aform of additions of EO and PO is a block polymer.

$\begin{matrix}{{{Narrow}\mspace{14mu} {ratio}} = {\sum\limits_{i = n_{{MAX} - 2}}^{i = n_{{MAX} + 2}}Y_{i}}} & (A)\end{matrix}$

In the formula (A), i is the number of moles of alkylene oxide added(the total number of moles of EO and PO which are added), n_(MAX) is thevalue of i of the fatty acid polyoxyalkylene alkyl ether whose number ofmoles of alkylene oxide added presents in the largest amount on massbasis among all the fatty acid polyoxyalkylene alkyl ether expressed bythe general formula (I), and Yi is a proportion (% by mass) of the fattyacid polyoxyalkylene alkyl ether whose number of moles of alkylene oxideadded is i in the entire fatty acid polyoxyalkylene alkyl ether.

<2> A surfactant composition for agricultural chemicals, containing:

the fatty acid polyoxyalkylene alkyl ether as defined in <1>;

water; and

C1-4 lower alcohol,

wherein a composition ratio expressed by the fatty acid polyoxyalkylenealkyl ether/the water/the C1-4 lower alcohol is 10% by mass to 60% bymass/10% by mass to 70% by mass/10% by mass to 70% by mass.

According to the present invention, various problems in the art can besolved, the aforementioned object can be achieved, and a surfactantcomposition for agricultural chemicals, which has an excellent surfaceactivity (solubilization ability, dispersibility, permeability, lowfoamability, and defoamability), excellent stability at low temperature,and excellent safety in the environment (e.g. no phytotoxicity and fishtoxicity) can be provided.

DETAILED DESCRIPTION OF THE INVENTION

The nonionic ester surfactant formed of fatty acid polyoxyalkylene alkylether for use in the present invention is fatty acid polyoxyalkylenealkyl ether, which is expressed by the general formula (I) below, andhas a narrow ratio of 55% by mass or more, where the narrow ratio isexpressed by the formula (A) below.

R¹CO(EO)_(m)(PO)_(n)OR²  (I)

In the general formula (I), R¹CO is a C14-22 saturated or unsaturatedfatty acid residue, R² is a C1-3 alkyl group, m and n respectivelyexpress average numbers of moles of EO and PO added, where m is aninteger of 2 to 10, and n is an integer of 1 to 4, EO expresses astructural unit of ethylene oxide, PO expresses a structural unit ofpropylene oxide, and EO and PO are added in the form of a block polymer.

$\begin{matrix}{{{Narrow}\mspace{14mu} {ratio}} = {\sum\limits_{i = n_{{MAX} - 2}}^{i = n_{{MAX} + 2}}Y_{i}}} & (A)\end{matrix}$

In the formula (A), i is the number of moles of alkylene oxide added(the total number of moles of EO and PO added), n_(MAX) is the value ofi of the fatty acid polyoxyalkylene alkyl ether whose number of moles ofalkylene oxide added is present in the largest amount on mass basisamong all of the fatty acid polyoxyalkylene alkyl ether expressed by thegeneral formula (I), and Yi is a proportion (% by mass) of the fattyacid polyoxyalkylene alkyl ether whose number of moles of alkylene oxideis i in the entire fatty acid polyoxyalkylene alkyl ether.

When the number of carbon atoms in the fatty acid residue R¹CO is 14 to22, the excellent surface activity such as surface tension,permeability, and low foamability, and excellent safety in theenvironment such as no phytotoxicity and no fish toxicity are attained.When the number of carbon atoms in R¹CO is in the range of 16 to 18, thesurface activity and safety in the environment are improved further.

The fatty acid residue R¹CO can be derived from myristic acid,5-methyltetradecanoic acid, 2,2-dimethyltetradecanoic acid,pentadecanoic acid, palmitic acid, zoomaric acid (9-hexadecenoic acid),margaric acid, stearic acid, oleic acid, vaccenic acid (11-octadecenoicacid), linoleic acid, linolenic acid, ricinoleic acid (caster oil),9,10-dihydroxyoctadecanoic acid (caster oil), elaidic acid, isostearicacid, or the like. As seen from the listed examples above, the fattyacid residue R¹CO may have a substituent such as a hydroxyl group.

Also, the fatty acid residue R¹CO may be derived from a mixture ofcompounds having the substituents, or derived from fatty acid having acomposition distribution originated from vegetable oils such as soyabean oil, rape seed oil, and palm oil. Especially, the productionquantity of the palm oil is largest among the vegetable oils, and thusthere are stable supplies of the palm oil. In addition, the fatty acidderived from the palm oil is preferable, as it has excellent oxidationresistance compared to soya bean oil or rape seed oil.

The fatty acid residue R¹CO is suitably selected depending on theintended purpose without any restriction. For example, in view of lowtemperature stability, a fatty acid residue having an unsaturated bond,such as oleic acid, linoleic acid, and linolenic acid, is preferable,especially those fatty acid methyl esters, which are in the equivalentform of the fatty acid residue R¹CO, having an iodine value of 60 to 150are preferable, and those having the iodine value of 70 to 130 are morepreferable. Moreover, in view of oxidation stability, the iodine valueof the fatty acid residue is particularly preferably 70 to 110. Specificexamples thereof include M 181 and M182, both manufactured by LionCorporation, which are fatty acid methyl esters derived from palm oil.

The number of carbon atoms contained in the lower alkyl group R² issuitably selected depending on the intended purpose without anyrestriction, but is 1 to 3, preferably 1 to 2, and more preferably 1,i.e. the lower alkyl group being a methyl group, because it can beeasily produced.

When the number of carbon atoms in the lower alkyl group R² is 4 ormore, the resulting surfactant composition may have higher fish toxicityand higher phytotoxicity. When the number thereof is 5 or more, inaddition to the above, the permeability of the resulting surfactantcomposition may be decreased. When R² is a hydrogen atom, thepermeability of the resulting surfactant composition may besignificantly decreased, and hence the functionality thereof as aspreading agent may be reduced.

The average number “m” of moles of ethylene oxide (EO) that have beenadded is the range of 2 to 10, preferably 3 to 7. When the averagenumber of moles thereof is smaller than 2, the permeability of theresulting surfactant composition decreases. When the average number ofmoles thereof is larger than 10, foamability of the resulting surfactantcomposition is excessively high, as well as having low permeability. Inview of desirable permeability and foaming ability of the resultingsurfactant composition, the average number of moles of EO that have beenadded is preferably in the range of 3 to 7.

The average number “n” of moles of propylene oxide (PO) that have beenadded is in the range of 1 to 4, preferably 2 to 4. When the averagenumber “n” of moles added is 5 or more, the fluid stability of theresulting surfactant composition may be low. When the average numberthereof is 0, the permeability of the resulting surfactant compositionmay be decreased.

The combination of the number of moles of EO added and the number ofmoles of PO added is preferably such combination that 3 to 7 moles of EOand 2 to 4 moles of PO, because with such combination, the resultingsurfactant composition has preferable permeability, low foamability,fluid stability, and safety (without giving any fish toxicity).

The form of addition of EO and PO is a block addition, and the order ofthe addition needs to be, as presented in the general formula (I), suchthat PO is added at the terminal (the side of —OR²).

By adding EO and PO in the form of the block addition where PO is addedat the terminal, the resulting surfactant composition attains lowfoamability, excellent permeability, and excellent low temperaturestability. Moreover, such surfactant composition has an excellent safetyin the environment in view of fish toxicity and the like. On the otherhand, when the form of the addition of EO and PO is a random addition,the resulting surfactant composition has poor permeability, and poorstability at low temperature. In addition, those having PO added, not atthe terminal, but at the side of the fatty acid residue R¹CO, have highfoamability, i.e. poor in low foamability.

The fatty acid polyoxyalkylene alkyl ether is suitably selecteddepending on the intended purpose without any restriction. The fattyacid polyoxyalkylene alkyl ether may be a mixture of alkylene oxideadducts having various numbers of moles of alkylene oxide added. In thiscase, such fatty acid polyoxyalkylene alkyl ether needs to have acertain distribution of added mole numbers specified by the narrow ratioexpressed by the formula (A).

The narrow ratio expressed by the formula (A) means a sum of alkyleneoxide adducts having n_(MAX) and alkylene oxide adducts having thenumber of moles of alkylene oxide added which is in the range of ±2moles from the n_(MAX), where n_(MAX) is the number of moles of alkyleneoxide added, which presents in the largest amount based on “% by mass”in the entire alkylene oxide adducts.

Here, the number of moles of alkylene oxide added is the total number ofmoles of EO and PO added. The adducts having the same number of moles ofalkylene oxide added includes a plurality of alkylene oxide adductshaving mutually different numbers of moles of EO added and differentnumbers of moles of PO added, but the same number of moles of alkyleneoxide added on the whole.

The narrow ratio expressed by Formula (A) is 55% by mass or more,preferably 60% by mass or more, and more preferably 65% by mass or more.The higher narrow ratio is more preferable. However, in the case where asolid catalyst is used in the production, the production time isextended due to low filtration speed of the catalyst after thecompletion of the reaction, which increases a production cost. In thecase where an alkali catalyst is used in the production, moreover, theproduction efficiency is lowered due to low yield resulted from thedistillation, which increases a production cost. For these reasons, theupper limit of the narrow ratio is practically 95% by mass or less. Whenthe narrow ratio is 55% by mass or more, the resulting surfactantcomposition has low foamability, and excellent defoamability and fluidstability.

The narrow ratio can be controlled by a production method of the fattyacid polyoxyalkylene alkyl ether expressed by the general formula (I).

The production method of the fatty acid polyoxyalkylene alkyl ether issuitably selected depending on the intended purpose without anyrestriction. Examples thereof include: a method in which a blockaddition polymerization of PO and EO are performed to fatty acid alkylester using a complex metal oxide catalyst (see JP-A No. 2000-144179); amethod in which a block addition polymerization is performed on a loweralcohol, which is an equivalent of R²O using the aforementioned complexmetal oxide catalyst (see JP-A 09-262456), and then the resultant issubjected to transesterification with suitable fatty acid ester, or theresultant is subjected to esterification with suitable fatty acid; and amethod in which PO and EO added to the lower alcohol by a block additionpolymerization using an alkali catalyst, followed by appropriatelyevaporating and removing unreacted lower alcohol or substances havinglow numbers of moles added to control the distribution of the numbers ofmoles added to have a desired narrow ratio, and then the resultant issubjected to transesterification with suitable fatty acid ester, or theresultant is subjected to esterification with suitable fatty acid.

When the block addition polymerization of PO and EO is performed to thefatty acid alkyl ester in the production of the fatty acidpolyoxyalkylene alkyl ether, a catalyst for use is suitably selectedwithout any restriction. For obtaining the fatty acid polyoxyalkylenealkyl ether having the desired narrow ratio without using otherpurification member such as evaporator, the catalyst for use ispreferably a complex metal oxide catalyst, such as baked catalysts ofhydrotalcite a surface of which is modified with metal hydroxide and/ormetal alkoxide, and a complex metal oxide catalyst such as magnesiumoxide to which metal ions (e.g. Al³⁺, Ga³⁺, In³⁺, Tl³⁺, Co³⁺, Sc³⁺,La³⁺, and Mn²⁺) whose surface is modification with alkali are added.

Specific examples of such catalyst include a catalyst which is obtainedby surface modifying alumina-magnesia complex oxide with metal hydroxideor metal alkoxide, where the alumina-magnesia complex oxide is obtainedby baking a coprecipitate of aluminum hydroxide and magnesium hydroxide,which is expressed by the general formula (2) below.

nMgO.Al₂O₃ .mH₂O  (2)

In the general formula (2), n is not particularly limited, butpreferably around 2.5, and m is not particularly limited.

The baking temperature of the coprecipitate is preferably 400° C. to950° C., more preferably 500° C. to 750° C.

The metal hydroxide used for the modification is suitably selecteddepending on the intended purpose without any restriction, but it ispreferably selected from hydroxides of alkali metals or alkali earthmetals, more preferably selected from sodium hydroxide and potassiumhydroxide.

The metal alkoxide is suitably selected depending on the intendedpurpose without any restriction, but is preferably selected from alkalimetals, and alkali earth metals, more preferably selected from sodiumalkoxide, and potassium alkoxide.

The production method of the modified catalyst is suitably selecteddepending on the intended purpose without any restriction. For example,there are methods such as a method in which baked alumina-magnesiacomplex oxide is modified with hydroxide or alkoxide of alkali metal oralkali earth metal in advance, and is used as a catalyst for a reaction,and a method in which a baked alumina-magnesia complex oxide is mixedwith metal hydroxide or metal alkoxide in fatty acid alkyl ester, whichis a raw material, in a reactor for alkoxylation to modify the catalystin the fatty acid alkyl ester, and then a reaction with alkylene oxideis performed.

The former method is not particularly limited, but is preferably amethod in which an aqueous solution or alcohol solution of metalhydroxide or metal alkoxide is sprayed onto the baked alumina-magnesiacomplex oxide, followed by drying or baking.

The latter method is not particularly limited, and the order for addingthe baked alumina-magnesia complex oxide and the metal hydroxide ormetal alkoxide to the raw material fatty acid alkyl ester is notparticularly limited. For addition, it is preferred that the metalhydroxide or metal alkoxide is added in the form of a lower alcoholsolution or aqueous solution for uniformly and more selectively partlymodify the acid centers of the surface of the catalyst.

The amount of the metal hydroxide or metal alkoxide used for themodification of the baked alumina-magnesia complex oxide is notparticularly limited, but is preferably 1% by mass to 20% by massrelative to the amount of the baked alumina-magnesia complex oxide.

In the case where the surface modification is not performed, the blockaddition reaction product having a desired narrow ratio may not beobtained. In such case, the desired narrow ratio of thereof may beobtained by the operation such as by evaporating substances having smallnumbers of moles of EO and PO added. Note that, in order to introduce POat the terminal, it is necessary to perform a block additionpolymerization in the order of PO and EO.

In the case the fatty acid polyoxyalkylene alkyl ether is produced bythe method in which a block addition polymerization is performed on alower alcohol, which is an equivalent of R²O using the aforementionedcomplex metal oxide catalyst, and then the resultant is subjected totransesterification with suitable fatty acid ester, or the resultant issubjected to esterification with suitable fatty acid, the complex metaloxide catalyst for use is not particularly limited, but can be selectedfrom those listed above. Moreover, the complex metal oxide catalyst maybe subjected to a surface modification, but in the case of the additionreaction to the lower alcohol, the desirable narrow ratio can beattained without performing the surface modification.

The addition reaction of ethylene oxide and propylene oxide using thesolid catalyst can be performed in accordance with the common method.For example, the reaction temperature is not specifically limited, butgenerally is 80° C. to 230° C., preferably 120° C. to 190° C. Thereaction pressure is, though it may be set depending on the reactiontemperature, generally 0 MPa to 0.8 MPa, preferably 0.2 MPa to 0.5 MPa(gauge pressure).

The amount of the catalyst for use is changed depending on the molarratio of alkylene oxide and fatty acid alkyl ester used in the reaction,but is generally 0.1% by mass to 20% by mass relative to the amount ofthe fatty acid alkyl ester.

In the case the fatty acid polyoxyalkylene alkyl ether is produced bythe method in which a block addition polymerization is performed on alower alcohol, which is an equivalent of R²O using the aforementionedcomplex metal oxide catalyst, and then the resultant is subjected totransesterification with suitable fatty acid ester, or the resultant issubjected to esterification with suitable fatty acid, a desirable narrowratio cannot be obtained only by the addition reaction.

In order to obtain a block adduct having PO unit at the terminal as afinal product in the present method, it is necessary to perform anaddition reaction of PO first, followed by performing an additionreaction of EO.

In this case, as a method for obtaining a desirable narrow ratio, thereis a method in which the unreacted raw material, adducts of low moles,and the like are removed from an intermediate product obtained from theaddition reactions of PO and EO, by distillation. In the case where theunreacted raw material and the like are removed by distillation, thedistillation is performed in the common method such as a vacuumdistillation. It is preferred that the amount of the unreacted rawmaterial be 2.5% by mass or less in the fatty acid polyoxyalkylene alkylether in view of permeability and fluid stability.

Moreover, the following methods are also preferable because thedistribution of the number of moles of PO added and the distribution ofthe number of moles of EO added can be separately controlled, and ablock adduct having a narrower distribution of the number of moles addedcan be easily obtained. Namely, they are a method in which unreactedsubstances and/or adducts of low moles are removed from an intermediateproduct 1 obtained from the addition reaction of PO, by distillation,and a method in which after the procedure of the former method, anaddition reaction of EO is performed to attain a block adduct (anintermediate product 2), and adducts of low moles are again removed fromthe intermediate product 2 by distillation.

In this case, the narrow ratio of the intermediate product 1 calculatedby Formula (A) is preferably 40% by mass or more in view of permeabilityand fluid stability, more preferably 50% by mass or more, and even morepreferably 55% by mass or more. Moreover, the residual amount of theunreacted raw material alcohol is preferably 2.5% by mass or less inview of permeability and fluid stability, and more preferably 1.0% bymass or less in the total amount of the fatty acid polyoxyalkylene alkylether.

Such PO adduct having a high narrow ratio is not particularly limited.As such PO adduct, a commercially available raw material, which isobtained by performing an addition reaction of PO to a lower alcoholsuch as tripropylene glycol monomethyl ether (e.g. product name: methylpropylene triglycol (MFTG), manufactured by Nippon Nyukazai Co., Ltd.),followed by superfractionation. Use of the PO adduct of a single numberof moles added, which does not substantially have a distribution, bysuperfractionation or the like is preferable, because the resultingsurfactant composition has particularly excellent permeability.

When the block adduct (the intermediate product 2) is obtained byperforming an addition polymerization of EO to the intermediate product1 having a narrow distribution of the numbers of moles added, theresidual intermediate product 1 to which EO has not been added oradducts of low moles of EO added are removed from the intermediateproduct 2 by distillation or the like so that the resultant has a sharpdistribution of numbers of moles of EO added. As a result, the resultingsurface composition has excellent foamability and defoamability.Moreover, when the resulting surface composition is formulated by mixingwith a solvent such as water or lower alcohol, such formulation hasexcellent low temperature stability, preventing uniformity,precipitation, or solidification. The removal of the adduct of low molesfrom the intermediate product 2 by distillation can be performed by acommon method such as a vacuum distillation. Moreover, those obtained bythe aforementioned production method may be produced and used singly orin an appropriate combination.

Examples of the production method of the fatty acid polyoxyalkylenealkyl ether include a method in which a block addition polymerization isperformed with lower alcohol, which is an equivalence of R²O using thecomplex metal oxide catalyst in the same manner (see JP-A No. 09-262456)followed by transesterification with suitable fatty acid ester orexterification with suitable fatty acid, and a method in which PO and EOare added and polymerized to the lower alcohol in the form of a blockpolymer using an, alkali catalyst, and then unreacted lower alcohol oradduct components of low moles are removed by distillation to control adistribution of numbers of moles added to thereby have a desirablenarrow ratio, followed by transesterification with suitable fatty acidester or exterification with suitable fatty acid. Here, the catalyst forused in the transesterification with suitable fatty acid ester orexterification with suitable fatty acid is suitably selected dependingon the intended purpose without any restriction. Examples thereofinclude basic catalysts such as lithium hydroxide, cesium hydroxide,sodium hydroxide, potassium hydroxide, magnesium hydroxide, bariumhydroxide, calcium hydroxide, sodium carbonate, potassium carbonate,sodium hydrogen carbonate, lithium chloride, sodium formate, and sodiummethoxide. Examples of acid catalysts include sulfuric acid, zirconiumsulfonate, p-toluene sulfonic acid (p-TS), benzene sulfonic acid (BS),and 2,4-dimethylbenzene sulfonic acid (2,4-DMBS). Examples of inorganicoxide catalysts include ZrO₂, TiO₂, SiO₂, PO₄, Al₂O₃, and ZnO.

The catalyst used for room temperature transesterification is suitablyelected depending on the intended purpose without any restriction.Examples of such catalyst include a tin compound, such as dialkyl tinchloride, dialkyl tin oxide, fluoroalkyl tin, and aminopropyl tin.

Other examples thereof include titanium compounds such as tetraisopropyltitanate, tetra-n-butyl titanate, tetraethanol amine titanate, andtetrastearyl titanate. In addition, examples thereof include, other thanthose listed above, samarium iodide, and N-heterocyclic carbine. Furtherexamples thereof include lanthanum(III)triisopropoxide ([La(Oi-Pr)₃]),lanthanum(III)tristrifluoromethylsulfonate ([La(OTf)₃]),lanthanumtrisacetylacetonate, lead compounds such as lead acetate andlead naphthenate, litharge, calcium naphthenate, and enzyme.

The surfactant composition for agricultural chemicals is used as a rawmaterial of an agricultural pesticide, and thus it is not desirable thattitanium or tin is left therein. Therefore, it is preferred that thesurfactant composition be subjected to an adsorption treatment orfiltration purification. Particularly preferable embodiment in view ofthe environment is such that sodium hydroxide, sodium hydrogencarbonate, or sodium methoxide is used as a catalyst fortransesterification or esterification, and then an adsorption treatmentor filtration purification is performed.

When the transesterification is performed with fatty acid ester such asfatty acid methyl ester in the course of the production of the fattyacid polyoxyalkylene alkyl ether, the residual amount of the fatty acidester in the resulting fatty acid polyoxyalkylene alkyl ether ispreferably 3.0% by mass or less, more preferably 2.0% by mass or less inview of the fluid stability and permeability.

The surfactant composition of the agricultural pesticide is suitablyused as a spreading agent of an agricultural pesticide containing anagricultural pesticide active ingredient, is suitably formulated andused in a fluid agricultural pesticide formulation as a dispersingagent, or solubilizing agent of an agricultural pesticide activeingredient and the like, or is suitably used together with a fluidagricultural pesticide as a spreading agent for agricultural chemicals.

In the case where the surfactant composition for agricultural chemicalsof the present invention is used as a spreading agent for agriculturalchemicals, for example, it is generally mixed in a chemical solution ofan agricultural pesticide and is used at the time when the agriculturalpesticide is sprayed. The concentration thereof for use is generallyabout 30 ppm to about 5,000 ppm in water, and is suitably adjusteddepending on an agricultural pesticide for use, or whether or not atargeted plant is easily wet.

In the case where the surfactant composition for agricultural chemicalsis used as a spreading agent for agricultural chemicals, it is preferredthat the surfactant be mixed with water and a solvent, and used as amixed solution, because the fatty acid polyoxyalkylene alkyl ether isnot easily dissolved in water.

Examples of the solvent include lower alcohol and glycols, since thesecan be easily dissolve the fatty acid polyoxyalkylene alkyl ethertherein, and are easily mixed with water.

In the present specification, the term “lower alcohol” means C1-4alcohol.

The lower alcohol is suitably selected depending on the intended purposewithout any restriction, and examples thereof include methanol, ethanol,isopropyl alcohol, n-propyl alcohol, isobutyl alcohol, and n-butylalcohol.

The glycols are suitably selected depending on the intended purposewithout any restriction, and examples thereof include ethylene glycol,and propylene glycol. Moreover, acetone, propylene carbonate,N-methylpyrrolidone, γ-butyrolactone, or the like may also be used asthe solvent. Concerning that it is released to the environment as aspreading agent for agricultural chemicals, ethanol, isopropyl alcohol,and isobutyl alcohol are preferable. In view of a high flash point forincreasing safety, isopropyl alcohol and isobutyl alcohol are suitable.

In the case where the surfactant composition for agricultural chemicalsis used as a spreading agent for agricultural chemicals, a proportion ofthe fatty acid polyoxyalkylene alkyl ether serving as a surfactant inthe surfactant composition for agricultural chemicals is 10% by mass to60% by mass, preferably 20% by mass to 40% by mass, a proportion ofwater therein is 10% by mass to 70% by mass, preferably 20% by mass to60% by mass, and a proportion of the lower alcohol therein is 10% bymass to 70% by mass, preferably 20% by mass to 50% by mass. Instead ofthe lower alcohol, a solvent formed of the glycols or a mixed solutionof the lower alcohol and the glycols can be used at the same proportion.

In the case where the surfactant composition for agricultural chemicalsis used as a spreading agent for agricultural chemicals, a specificexample of a formulation of the surfactant composition for agriculturalchemicals is consisted of 30% by mass of a surfactant of the fatty acidpolyoxyalkylene alkyl ether; 30% by mass of water; and 40% by mass ofisopropyl alcohol (i.e. a surfactant of the fatty acid polyoxyalkylenealkyl ether/water/isopropyl alcohol=30% by mass/30% by mass/40% bymass), which is preferable in view of its excellent low temperaturestability.

In addition to the above, the surfactant composition for agriculturalchemicals serving as a spreading agent for agricultural chemicals cancontain a sticking agent such as carboxymethylcellulose, Arabian gum,and casein, and a dispersing agent such as a naphthalenesulfonicacid-formaldehyde condensate, and lignin sulfonate, if necessary.

The surfactant composition for agricultural chemicals can be used, as anactivator for agricultural chemicals, for a functional spreading agent(adjuvant), water dispersible agent, emulsifier, and dispersing anddissolving agent. Moreover, it can be used as a surfactant foragricultural chemicals such as a bactericide, insecticide, acaricide,weedkiller, and plant growth regulator.

In the case where the surfactant composition for agricultural chemicalsis used as the dispersing and dissolving agent for a preparation of anagricultural pesticide, an amount of the surfactant composition foragricultural chemicals for use as a surfactant is about 5% by mass toabout 50% by mass.

The present invention can provide a surfactant composition, which haslow foamability, excellent defoamability, and excellent low temperaturestability, prevents separation (heterogeneity), precipitation, andsolidification, when it is formulated as a preparation where thesurfactant composition is mixed with a solvent such as water, loweralcohol, and the like as mentioned above, and which is suitably appliedand easily handled as a spreading agent for agricultural chemicals, or adispersing and dissolving agent for a preparation of an agriculturalpesticide.

Since this surfactant composition is an excellently environmentally safesurfactant composition, which can be used in the field of agriculturalpesticides, the surfactant can also be used as a surfactant in thefields of engineering works, energy industries, in which the surfactantwill be released in the environment.

EXAMPLES

The present invention will be more specifically explained throughExamples thereof, hereinafter. However, these Examples shall not beconstrued as to limit a scope of the present invention. The evaluationmethods and analysis methods used in Examples are shown below.

(1) Evaluation Method (i) Foaming Power and Defoamability

To a 1,000-mL graduated cylinder, 100 mL of a test solution having anactive ingredient concentration of 1,000 ppm was added. To thissolution, nitrogen gas was introduced from the bottom of the cylinder atthe rate of 1,000 mL/min. for 3 minutes using a glass ball filter(Filter Particle No. 4 (5 μm to 10 μm in size), manufactured byKinoshita Rika Kogyo Co., Ltd.). Just after the completion of theintroduction of the nitrogen gas, a foam height was measured, and wasdetermined as a foaming power. In addition, the defoamability wasdetermined based on the foam height just after the completion of theintroduction, and the height thereof 5 minutes after the completion ofthe introduction, using the following formula.

Defoamability(%)=(foam height just after the completion−foam height 5minutes later)/foam height just after the completion×100

The foaming power and defoamability were evaluated based on thefollowing criteria.

<Evaluation Criteria of Foaming Power (Foam Height)>

A: 0 mm or higher but lower than 90 mm

B: 90 mm or higher, but lower than 120 mm

C: 120 mm or higher

<Evaluation Criteria of Defoamability>

A: 70% or more

B: 40% or more but less than 70%

C: less than 40%

(ii) Permeability (Wettability)

A test was carried out in accordance with the Draves method. A piece ofwool knit cloth was cut out in the size of 20 cm in length and 3 cm inwidth to prepare a sample cloth. A wire tool was provided so that a wireanchor part of the tool would stay on the bottom of a 1,000-mL graduatedcylinder, and the wire anchor part and a snake pin hook (about 0.1 g)were connected with a nylon thread (about 3 cm). A test solution wasprepared by diluting each surfactant sample to 30 ppm with hard waterhaving a hardness index of 3, and was added to the 1,000-mL graduatedcylinder. One side of the test cloth was hanged on the snake pin hook,and the wire tool was placed in the 1,000-mL graduated cylinder in whichthe test solution was provided so that the wire anchor portion was sankand located on the bottom of the cylinder and the test cloth was floatedin the test solution. The time from when the snake pin hook was placedin the test solution to when the snake pin hook started to sink (whenthe thread between the hook and the anchor lost tension) was measured.The shorter the time is, more preferable the permeability is. The timeshorter than 30 second was determined as acceptable, and the time equalto or longer than 30 seconds was determined as unacceptable.

(iii) Fluid Stability Test

A solution was prepared with 30 parts by mass of a surfactant sample, 30parts by mass of ion-exchanged water, and 40 parts by mass of isopropylalcohol, and the solution was stirred until it became homogeneous. Then,the resulting solution was placed in a sample bottle, and the samplebottle was sealed, and placed in a constant temperature oven thetemperature of which was set to −5° C. for 72 hours. After this storageperiod, the solution which kept its homogeneous state at −5° C. wasdetermined as A, the solution which had precipitates or caused fluidseparation, but recovered its homogeneous state when it was heated to20° C. was determined B, and the solution which did not recover theprecipitation or fluid separation was determined as C.

(iv) Solubility

An aqueous solution of each surfactant sample was prepared at theconcentration of 1,000 ppm as a sample solution. To 4 mL of this samplesolution, an oil soluble coloring agent Yellow OB was added in an amountof 40 mg as an insoluble substance, and the mixture was agitated at roomtemperature for 24 hours. Thereafter, the resulting solution wasfiltered through a pretreatment filter (Chromatodisk, manufactured by GLSciences Inc., 13N, non-water system, nonstelarized) having an openingsize of 0.45 μm, followed by adding an equal amount of ethanol. Anabsorption of the resulting solution was measured at 450 nm. As thedissolved amount, the amount which was 30 ppm or more was determined asacceptable, and the amount less than 30 ppm was determined asunacceptable.

(v) Biodegradability

A test was performed with reference to a degradation test of a chemicalsubstance by microbes or the like in accordance with Act on theEvaluation of Chemical Substances and Regulation of their manufacture,etc. (CSCL). Specifically, activated sludge was added in an amount of 30ppm (solid contents) was added as a seeding source to a test solutionhaving a sample concentration of 100 ppm, and a biochemical oxygendemand (BOD) and the total oxygen demand (TOD) where measured over time.The results of the biodegradation degree, i.e. BOD/TOD (%), wereevaluated based on the following criteria.

A: The biodegradation degree reached 60% within 28 days.

B: It took 29 days or longer for the biodegration degree to reach 60%,or the sample was only decomposed at a certain amount but not more thanthat amount.

(vi) Fish Toxicity

A fish toxicity value, a median tolerance limit (TLm)(48 hours), wasmeasured on Japanese variety of cyprinodonts with reference to “71.Acute toxycity test for fish”, defined in Testing methos for industrialwastewater JIS K 0102, namely the median lethal concentration (ppm) wasmeasured after 48 hours. The result which was 100 ppm or higher wasdefined as acceptable, and the result which was lower than 100 ppm wasdefined as unacceptable.

(vii) Phytotoxicity

The sample was sprayed to cabbage and garden pea as an active ingredient(5,000 ppm) of a spreading agent, and a rate of phytotoxicity occurredwas determined 5 days later. The result of the rate of the phytotoxicitywhich was less than 30% was determined as acceptable, and the result ofthe rate thereof which was 30% or more was determined as unacceptable.

(3) Analysis Method

The analysis method used is described hereinafter. The average numbersof moles of EO, and PO added were calculated from the balance of themasses of the charged raw materials and alkylene oxide. Note that, inthe case where the distillation was performed after the additionreaction of EO and PO, the average number of moles added was determinedby ¹H-NMR described in (i) below.

(i) Calculation Method of Average Number of Moles Added

The obtained compound (30 mg) was dissolved in 4 mL ofdeuterochloroform, and the solution was then measured by ¹H-NMR (300MHz, FT NMR SYSTEM JNM-LA300, manufactured by JEOL Ltd.). The chemicalshift of the deuterochloroform was calculated, using 7.30 ppm as astandard, from the integral value ratio of chemical shift of each peak,0.87 ppm (terminal methyl of fatty acid), 1.13 ppm to 1.15 ppm (sidechain methyl of PO), 3.32 ppm to 3.66 ppm (methine and methylene of PO),and 3.52 ppm to 3.71 ppm (methylene of EO).

(ii) Measurement of Distribution of Numbers of Moles EO and PO Added,and Calculation Method of Narrow Ratio

The distributions of numbers of moles of EO and PO added of the finalproduct and intermediate product were measured in the following manner.

Condition of Device: gas chromatograph: HP-6890 Mass Selective Detector(GC-MS),

Detector: FID

Column: UltraALLOYPY-1, 0.25 mm in diameter, 30 m in length, filmthickness of 0.25 μm

Condition of Analysis Injection: 380° C., Detector: 380° C.

Initial: 50° C.→360° C. (20 min), temperature increasing rate: 10°C./min, carrier gas: HeSplit ratio: 50/1

The sample (0.5 g) was dissolved in 10 g of acetone, 1 μL of theobtained solution was introduced to the device, and a concentration (%)per mole of EO (PO) added was measured. The total proportion of themaximum peak of the obtained chromatogram and adducts in the range of ±2moles of the maximum peak (the total of adducts in range of 5 moles) wasdetermined as a narrow ratio.

$\begin{matrix}{{{Narrow}\mspace{14mu} {ratio}} = {\sum\limits_{i = n_{{MAX} - 2}}^{i = n_{{MAX} + 2}}Y_{i}}} & (A)\end{matrix}$

(iii) Determination of Amount of Unreacted Fatty Acid Methyl Ester orUnreacted Methanol Contained in Intermediate Product 1 or 2

(1) For Unreacted Fatty Acid Methyl Ester

As internal standard, 0.06 g of methyl laurate and 2 g of a sample wereprepared and dissolved in 4 g of acetone, and the obtained solution (2μL) was introduced to a device. An analytical curve was formed from thepeak area of the internal standard, and the peak area obtained when theconcentration of methyl laurate was changed, and an amount of anunreacted component contained the sample was determined.

(2) For Unreacted Methanol

A sample (1 μL) was introduced to a device without diluting with asolvent, and an amount of unreacted methanol was calculated from thearea % of the obtained chromatogram.

<Conditions for Device>

Gas chromatograph: Shimadzu GC-14A, detecting element: FID, Column: madeof glass 3 mm in diameter×1 m, fillers: 2% silicon OV-1 (60/80 mesh)

—Universal Conditions—

Injection: 320° C., Detecter: 320° C., N₂: 50 mL/min, H₂: 0.75 kg/cm²,Air: 0.5 kg/cm²

—For Unreacted Methyl Ester—

Initial: 100° C.→+230° C. (increasing rate of temperature: 10°C./min)→320° C. (increasing rate of temperature: 30° C./min), durationfor maintaining the temperature: 22 min

—For Unreacted Methanol—

Initial: 50° C.→320° C. (maintaining for 20 min), increasing rate oftemperature: 10° C./min

Example 1

An alumina-magnesia complex oxide (Kyowado 300, manufactured by KyowaChemical Industry Co., Ltd.) expressed by the chemical formula2.5MgO.Al₂O₃.nH₂O was baked at 750° C. for 3 hours under nitrogen gasstreams to thereby obtain a baked alumina-magnesia complex oxide (Al/Mgmolar ratio=0.44/0.56) catalyst. Into a 4-L autoclave, 1,073 g of methyloleate (fatty acid methyl ester derived from C18 fractions derived frompalm oil, product name: PASTELL M182, manufacturer: Lion Corporation,iodine value: 91), 5 g of the obtained catalyst, and 0.58 g of 40% KOHas a modifying agent for the catalyst were added, and the inneratmosphere of the autoclave was replaced with nitrogen gas twice.

Thereafter, the temperature was increased to 180° C., the pressureinside the reaction vessel was returned to normal pressure by nitrogen,and then 628 g of PO (3 moles relative to 1 mole of methyl oleate) wasgradually introduced to the vessel. The pressure just after thecompletion of the introduction of PO was 0.48 MPa, and was reduced asthe reaction progressed. The PO addition reaction was continued untilthe pressure became constant at 0.22 MPa in 2 hours. A portion of theobtained intermediate product 1A was sampled, and then analyzed by gaschromatography. As a result, the sample contained 12.8% by mass ofunreacted fatty acid methyl ester.

Then, after the nitrogen purge was performed and the temperature wasincreased in the aforementioned manners, 794 g of EO (5 moles relativeto 1 mole of methyl oleate) was gradually introduced to the vessel. Thepressure just after the completion of the introduction of EO was 0.5MPa, and was reduced as the reaction progressed. The EO additionreaction was continued until the pressure became constant at 0.24 MPa in0.5 hours time. The obtained reaction product was filtered using diatomearth to thereby obtain a final product. The compound 1A obtained by ablock addition reaction of PO and EO contained 1.1% by mass of unreactedfatty acid methyl ester. Results of measurements and evaluation wereshown in Tables 1 and 2.

Example 2

A compound 1B was obtained by a block addition reaction of PO and EO inthe same manner as in Example 1, provided that the amount of PO addedwas changed to 565 g (2.7 moles relative to 1 mole of methyl oleate),and the obtained intermediate product 1B was subjected to vacuumdistillation by reducing the pressure to 10 Torr or lower, whileincreasing the temperature stepwise from 175° C. to 200° C. stepwise, soas to remove unreacted methyl ester contained in the intermediateproduct 1B. The intermediate product 1B contained 0.8% by mass ofunreacted fatty acid methyl ester. The compound 1B obtained by furthersubjecting to an addition reaction of EO contained 0.3% by mass ofunreacted fatty acid methyl ester. The results of measurements andevaluation are shown in Tables 1 and 2.

Example 3

A compound 1C was obtained by performed a block addition reaction of POand EO in the same manner as in Example 2, provided that 40% KOH was notadded as the modifying agent for the catalyst. The intermediate product1C after the vacuum distillation contained 1.8% by mass of fatty acidmethyl ester. The compound 1C obtained by further subjecting to anaddition reaction of EO contained 1.6% by mass of unreacted fatty acidmethyl ester. The results of measurements and evaluation are shown inTables 1 and 2.

Comparative Example 1

A final product was obtained in the same manner as in Example 1,provided that a mixture of 794 g of EO (5 moles relative to 1 mole ofmethyl oleate) and 628 g of PO (3 moles relative to 1 mole of methyloleate) was gradually introduced to the vessel, and then a randomaddition reaction of EO and PO was performed. The pressure in the vesselwas 0.48 MPa just after the completion of the mixture, but was reducedas the random addition reaction of EO and PO progressed. The randomaddition reaction was continued until the inner pressure became constantat 0.24 MPa in 2 hours time. The compound 1D obtained by the randomaddition reaction of EO and PO contained 1.2% by mass of unreacted fattyacid methyl ester. The results of measurements and evaluation are shownin Tables 1 and 2.

Comparative Example 2

A final product was obtained in the same manner as in Example 1,provided that the order of the block addition was changed from “PO firstand then EO” to “EO first and then PO”. The compound 1E obtained by theblock addition reaction of EO and PO contained 1.1% by mass of unreactedfatty acid methyl ester. The results of measurements and evaluation areshown in Tables 1 and 2.

Comparative Example 3

A final product was obtained in the same manner as in Example 1,provided that 40% KOH was not added as the modifying agent for thecatalyst. The compound 1F obtained by the block addition reaction of POand EO contained 4.9% by mass of unreacted fatty acid methyl ester. Theresults of measurements and evaluation are shown in Tables 1 and 2.

Example 4

Into a 4-L autoclave, 387 g of methanol (manufactured by Junsei ChemicalCo., Ltd.), and 1 g of NaOH as a catalyst were added, and the inneratmosphere of the autoclave was replaced with nitrogen gas twice.Thereafter, the temperature was increased to 90° C., and then 1,405 g ofPO (2.0 moles relative to 1 mole of methanol) was gradually introducedto the vessel to proceed an addition reaction.

After the completion of the reaction, the temperature was increasedstepwise from 75° C. to 100° C. under normal pressure, and distillationwas performed until the methanol residue became 1% or lower, to therebyobtain an intermediate product 2A1. The average number of moles of POadded of the intermediate product 2A1 was 2.4 moles. Thereafter, to 857g of the intermediate product 2A1, 881 g of EO (4 moles relative to 1mole of the intermediate product 2A1) was introduced, and an additionreaction was performed. After the addition reaction was completed,distillation was again performed by reducing the pressure to 10 Torr,while increasing the temperature stepwise from 175° C. to 220° C. Into areaction vessel fitted with a stirring blade, 853 g of the obtainedintermediate product 2A2, 614 g of methyl oleate (PASTELL M182, iodinevalue: 91) (1.03 moles relative to 1 mole of the intermediate product2A2), and 7.3 g of sodium hydrogen carbonate were added, and thetemperature was increased from 60° C. to 210° C. under stirring whilereducing the pressure stepwise from normal pressure to 10 Torr tothereby perform transesterification. The compound 2A obtained by thereaction contained 1.6% by mass of unreacted fatty acid methyl ester.The results of measurements and evaluation are shown in Tables 1 and 2.

Example 5

An addition reaction of PO was performed in the same manner as inExample 4, provided that the amount of PO introduced was changed to2,108 g (3 moles relative to 1 mole of methanol). After the completionof the reaction, distillation was performed under normal pressure whileincreasing the temperature stepwise from 75° C. to 130° C., until theproportion of the methanol residue and methanol-1PO product was 1% orless. Then, vacuum distillation was further performed by increasing thetemperature stepwise from 175° C. to 220° C. while reducing the pressurestepwise to 5 Torr, and then the distillate was collected so as to givean intermediate product 2B1 from which the portion of high boilingsubstances had been removed. The average number of moles of PO added ofthe intermediate product 2B1 was 3 moles.

To the intermediate product 2B1, an addition reaction of EO wasperformed in the same manner as in Example 4 to thereby obtain anintermediate product 2B2. then, to the intermediate product 2B2,transesterification was performed in the same manner as in Example 4, tothereby obtain a compound 2B. The obtained compound 2B contained 1.6% bymass of unreacted fatty acid methyl ester. The results of measurementsand evaluation are shown in Tables 1 and 2.

Example 6

A block addition reaction of PO and EO was performed in the same manneras in Example 4 to thereby obtain an intermediate product 2C2, providedthat an addition reaction of PO was performed in the manner that theamount of PO introduced was changed to 1,686 g (2.4 moles related to 1mole of methanol) and the distillation was not performed after theaddition reaction of PO, and to the intermediate product 2C2transesterification reaction was performed in the same manner as inExample 4 to thereby obtain a compound 2C.

The intermediate product 2C1 contained 1.9% by mass of unreactedmethanol, and the obtained compound 2C contained 1.7% by mass ofunreacted fatty acid methyl ester. The results of measurements andevaluation are shown in Tables 1 and 2.

Comparative Example 4

A compound 2D was obtained in the same manner as in Example 6, providedthat the addition reaction of PO was performed in the manner that theamount of PO introduced was changed to 2,108 g (3 moles relative to 1mole of methanol), the addition reaction of EO was performed in themanner that the amount of EO introduced was changed to 1,289 g (5 molesrelative to 1 mole of methanol), and vacuum distillation was notperformed after the addition reaction of EO. The intermediate product2D1 contained 10.3% by mass of unreacted methanol, and the obtainedcompound 2D contained 1.6% by mass of unreacted fatty acid methyl ester.The results of measurements and evaluation are shown in Tables 1 and 2.

Note that, the sample used for each example was also evaluated in termsof biodegradation ability, fish toxicity, and phytotoxicity, and as aresult, it was confirmed that all the samples had excellentbiodegradation ability (evaluation: A), and were highly safe in theenvironment, which passed the acceptable levels of the results of thetests for fish toxicity and phytotoxicity.

TABLE 1 EO/PO Average number Narrow Sample Starting addition of molesadded Position ratio No. material Catalyst form EO PO of PO (mass %) Ex.1 1A Fatty acid Modified Block 5 3 Terminal 68 methyl ester solid Ex. 21B Fatty acid Modified Block 5 3 Terminal 76 methyl ester solid Ex. 3 1CFatty acid Non-modified Block 5 3 Terminal 60 methyl ester solid Comp.1D Fatty acid Modified Random 5 3 Inner 69 Ex. 1 methyl ester solidportion Comp. 1E Fatty acid Modified Block 5 3 Inner 66 Ex. 2 methylester solid portion Comp. 1F Fatty acid Non-modified Block 5 3 Terminal43 Ex. 3 methyl ester solid Ex. 4 2A Methanol NaOH Block 5 3 Terminal 65Ex. 5 2B Methanol NaOH Block 5 3 Terminal 71 Ex. 6 2C Methanol NaOHBlock 5 3 Terminal 61 Comp. 2D Methanol NaOH Block 5 3 Terminal 48 Ex. 4

TABLE 2 Foaming power Defoamability Sample Foam Value Permeability FluidNo. height (mm) Evaluation (%) Evaluation (sec.) stability Ex. 1 1A 62 A79 A 18 B Ex. 2 1B 49 A 85 A 14 A Ex. 3 1C 85 A 71 A 28 B Comp. 1D 113 B51 B 45 C Ex. 1 Comp. 1E 176 C 36 C 83 C Ex. 2 Comp. 1F 97 B 64 B 37 CEx. 3 Ex. 4 2A 73 A 75 A 22 B Ex. 5 2B 55 A 82 A 16 A Ex. 6 2C 89 A 70 A29 B Comp. 2D 143 C 45 C 57 C Ex. 4

1. A surfactant composition for agricultural chemicals, comprising:fatty acid polyoxyalkylene alkyl ether expressed by the followinggeneral formula (I),R¹CO(EO)_(m)(PO)_(n)OR²  (I) where R¹CO is a C14-22 saturated orunsaturated fatty acid residue; R² is a C1-3 alkyl group; m and n eachexpress an average number of moles added, where m is an integer of 2 to10, and n is an integer of 1 to 4; and EO expresses a structural unit ofethylene oxide, and PO expresses a structural unit of propylene oxide,where a form of additions of EO and PO is a block polymer, wherein thefatty acid polyoxyalkylene alkyl ether has a narrow ratio of 55% by massor more, where the narrow ratio is expressed by the following formula(A): $\begin{matrix}{{{Narrow}\mspace{14mu} {ratio}} = {\sum\limits_{i = n_{{MAX} - 2}}^{i = n_{{MAX} + 2}}Y_{i}}} & (A)\end{matrix}$ where i is the number of moles of alkylene oxide added(the total number of moles of EO and PO which are added), n_(MAX) is thevalue of i of the fatty acid polyoxyalkylene alkyl ether whose number ofmoles of alkylene oxide added presents in the largest amount on massbasis among all the fatty acid polyoxyalkylene alkyl ether expressed bythe general formula (I), and Yi is a proportion (% by mass) of the fattyacid polyoxyalkylene alkyl ether whose number of moles of alkylene oxideadded is i in the entire fatty acid polyoxyalkylene alkyl ether.
 2. Asurfactant composition for agricultural chemicals, comprising: the fattyacid polyoxyalkylene alkyl ether as defined in claim 1; water; and C1-4lower alcohol, wherein a composition ratio of the surfactant compositionexpressed by the fatty acid polyoxyalkylene alkyl ether/the water/theC1-4 lower alcohol is 10% by mass to 60% by mass/10% by mass to 70% bymass/10% by mass to 70% by mass.